Toxic chemicals in pet flea treatments harming wildlife, UK study warns

Flea treatment chemicals fipronil and imidacloprid also implicated in lower cognitive scores in children with autism Toxic chemicals found in pet flea treatment are devastating wildlife in rivers, parks and special conservation areas and the government should take urgent action to limit their use, according to a study. Chemicals that are banned for use as pesticides but still used in liquid flea treatments are causing potentially irreversible harm to aquatic life as well as decimating birds and pollinators, according to the study published on Thursday. It found that flea treatment chemicals fipronil and imidacloprid have also been implicated in lower cognitive and adaptive scores in children with autism and was ranked by the Environment Agency as being the chemical with the highest risk to human health in English waters. The assessment by ecologist Matt Shardlow, who carried out one of the first studies into the impact of flea treatments nine years ago, says urgent action is needed to prevent these chemicals doing more damage. “The more you look at this, the worse it gets,” said Shardlow from the Wildlife and Countryside Link. “The level of new alarming information showing the scal

May 21, 2026 → May 21, 2026